Help please

Cub Cadet LT42 w/ Kohler ks540 motor here. Began the other day where it would run and mow fine for about an hour then it would just randomly die, and would not restart. Suspected fuel issue so I just replaced the carb, fuel filter, threw in new spark plug, and cleaned the magneto for good measure.

Now, it runs for ~10 seconds on cold start, then dies and will not restart despite repeated attemptson and off choke. If I let it sit for 5-10 minutes then it'll start and do the same thing. I have no idea what else it could be as I've pretty much replaced everything other than the magneto itself. It doesn't appear to have an actual fuel pump.

Any thoughts on what else it could be? Anyone else experienced this issue?

TYIA!
Terry